The present invention relates to the field of microorganism, in particular to a strain of marine oil-degrading bacteria and its application.
Marine microorganism is the generic name of ocean lower organisms in the ocean with small size and simple structure, including bacteria, fungus, actinomycetes, mould, yeast, viruses, chlamydia, mycoplasma, phages, micro algae and tiny protozoans, etc. Before the 1990s, there were few chemical researches and reports on secondary metabolites of marine microorganisms, and the hot topic had been terrestrial fungal resources; after 1990s, chemical researches and reports on secondary metabolites of marine microorganisms significantly increased; The largest number of new compounds were found in 1998 and 2000, and the number of new compounds derived from marine microorganisms also increases. Many compounds have new skeletons, indicating that marine microorganisms have unique metabolic and physiological mechanisms, and are the potential rich resource for new compounds and drug lead compounds.
Alcanivorax is an important alkane degrading bacteria in marine oil pollution environment. Currently, this kind of bacteria has been separated out or detected in surface seawater or in deep-sea sediments around the world. Six genera have been reported, the first one is Alcanivorax borkumensis SK2, which was obtained through separation by Yakimov et al in 1998, and can produce glycolipids surface active agent and glucose lipids (one anhydroglucose unit links four 3-OH fatty acid); Alcanivorax dieselolei B-5 separated from surface seawater of Yellow Seacan reduce fermentation broth surface tension to less than 30 mm/m, in the induction medium with cetane as the only carbon source, and is identified as proline lipid (hexadecanoic acid and proline lipid can be dehydrated and condensed to a linear lipid peptide.) Biosurfactant is the metabolites generally produced by microorganisms (especially some fungus and bacteria) under certain culture conditions, including glycolipids, lecithin, polysaccharide compounds, lipoprotein-lipid polypeptides, hydroxyl compound and cross linking fatty acids, etc. Non-polar hydrophilic group of biosurfactant is generally long chain fatty acid or beta hydroxy fatty acid, alpha-alkyl-beta hydroxy fatty acid; while polar hydrophilic group has various types, such as carbohydrate, amino acids, cyclic peptides, phosphates, alcohols, etc., and they generally have batter performance of lowering surface tension and interfacial tension.
Biosurfactant has some unique characteristics that common synthetic surfactants do not have: generally features lower critical micelle concentration, less dosage and high efficiency; and is biodegradable, non-toxic, and environmentally friendly; They can be used in the fields of environmental protection, cosmetics, drugs and food additives; with stable chemical structures and property, biosurfactants can be used in some extreme environments such as high temperature, high salt, and high pH, etc.; Biosurfactants can be classified intoglycolipid, lipopeptide, lipoprotein, phospholipid, fatty acid, polymeric surfactant and granular surfactant. The hydrophilic group of lipopeptide biosurfactant is composed of oligopeptide or amino acids, while the hydrophobic group consists of fatty acids, and the lipopeptide is usually a mixture formed by a variety of heterogeneous monomers. The chain length of fatty acid in the lipopeptide, the number of branched chains and composition of amino acid are so variable that the lipopeptide biosurfactant is in a great variety, the representative of which includes surfactin, lichenysin, fengycin, iturin, mycosubtilin, and bacillomycin, etc. The lipopeptides currently found mainly belong to family Bacillus, such as B. subitilis. B. circulans, B. cereus, B. polymyxa, B. mesentericus and the like. In addition to Bacillus, some other microorganisms, including mycobacterium fortuirum, Streptomyces canus, Pseudomonas fluorescens, and serratiamarcescens, etc., also produce lipopeptides.
TABLE 1several important microbial surfactantssource and their characteristicsliquid surfaceInterfacialtensiontensionlipopeptidesMicrobiological(mN/m)CMC(mN/m)Peptide-lipidB. licheniformis27  12-20 0.1-0.3SerrawettinS. marcescens28-33//ViscosinP. fluorescens26.5150/SurfactinB. subtilis27-3223-1601